Centrifuges are commonly used to separate slurries into their constituent components via the imposition of centrifugal force. The slurries usually include at least two phases each having a density that is different from the other. These phases are generally a combination of liquids, solids, and/or gases. To generate the centrifugal force required to separate the slurry into its components, the centrifuge usually includes a high-speed rotating vessel into which the slurry is fed. This vessel is referred to by those skilled in the pertinent art to which the present invention pertains as a “bowl.” Once in the rotating bowl, the slurry is entrained in the rotation and centrifugal force acts on the slurry causing it to separate intro its constituent components. Outlets are typically positioned around the periphery of the bowl to allow for the removal of at least one of the separated constituents from the bowl.
One type of centrifuge commonly employed to accomplish the above-described separation is referred to by those skilled in the pertinent art as a disc-nozzle centrifuge. In this type of machine, the rotating bowl includes a plurality of nozzles circumferentially positioned around the outermost periphery of the bowl. Each nozzle includes an inlet portion in communication with an interior area defined by the rotor bowl and an outlet to allow separated material to escape from the rotor bowl. During operation, the slurry is typically fed into the bowl and acted on by centrifugal forces so that the heavier phase of the slurry collects at the inner periphery of the bowl and enters the nozzles where it is discharged from the bowl. The nozzles can also be positioned around a peripheral surface other than the outermost periphery of the rotor bowl. In cases where the nozzles are positioned at a smaller radius from the rotational axis, less horsepower is required to operate the centrifuge.
Sometimes, due to wear or other maintenance issues, it is necessary to remove the nozzles from the bowl. This can be problematic in that the nozzles are typically held in the bowl via the frictional engagement of a portion of the nozzle with a portion of the bowl. Historically, the nozzles have been configured with a slot to allow them to be turned away from the frictional fit using a screwdriver. Once the frictional fit is overcome the nozzle can be positioned to be pulled from the bowl. However, since the screwdriver used to turn the nozzle is unable to exert a pulling force on the nozzle it is often quite difficult to remove the nozzle from the bowl. Generally, resort has been had to prying the nozzle from the bowl which can result in damage to one or both of the nozzle and the bowl.
Another problem sometimes occurs when inserting the nozzle into the bowl. In order for the centrifuge to function properly the nozzle must be correctly aligned relative to the bowl. By employing the above-described slot and screwdriver to turn the nozzle into the frictional fit, it is possible to not fully rotate the nozzle relative to the bowl, thereby resulting in an improper nozzle orientation.
Still another problem associated with the above-described prior art nozzles results from there being insufficient material at the end of a nozzle to accommodate the slot for the screwdriver. This results in the nozzle discharge having to be positioned in a less than optimal location and orientation (i.e., closer to the inlet of the nozzle such that the flow path between the inlet and the nozzle outlet of the discharge has a relatively tight radius or such that the fluid is dispelled substantially radially from the nozzle). Depending on the nozzle discharge orientation, considerably more or less power is required to operate the centrifuge.
Even when the above-described prior art nozzles are properly positioned, large amounts of horsepower are required to drive the centrifuge. A large part of the horsepower requirement is due to the operation and design of the nozzles. Properly orienting the nozzle discharge can have dramatic effects on the amount of horsepower required to drive the centrifuge bowl. A drawback of the above-described nozzle is that the slot does not allow the nozzle discharge to be located closer to the outermost surface of the nozzle. This in turn results in a less than optimal nozzle discharge angle relative to the periphery of the bowl.
Based on the foregoing, it is the general object of the present invention to provide a centrifuge nozzle, and a nozzle insertion and extraction tool that improves upon or overcomes the problems and drawbacks of the prior art.